Equilibrium : KspSaturation (12 Variations)
Zn(OH)2 has a Ksp of 4.5 x 10-17. If you have a solution of Zn(OH)2 that has a hydroxide ion concentration equal to 4.6 x 10-6 mol/L, the solution is ... (Assume that the only relevant reaction is the solubility-product equilibrium.)

Thermodynamics : ProbabilityEnergyDist (23 Variations)
Consider a system that has two indistinguishable molecules that can occupy three different energy levels (having energies of 1kJ, 2kJ and 3kJ, respectively). What is the probability that the molecules will have a total energy of 2 kJ?

Equilibrium : CommonIonEffect (9 Variations)
The molar solubility of lead(II) fluoride (PbF2) is
2.1 x 10-3 mol/L in pure water at 25oC. What is the molar solubility of lead(II) fluoride in 0.10 M NaF at 25oC? (Assume that the only relevant reaction is the solubility-product equilibrium.)

Equilibrium |

Chemometrics

Equilibrium : ConcFromKsp (8 Variations)
The Ksp of BaF2 is
1.7 x 10-6 mol/L in water at 25oC. What is the concentration of barium ions in equilibrium with solid barium fluoride? (Assume that the only relevant reaction is the solubility-product equilibrium.)

You have 0.50 mol SbCl5 present initially in a 1.0L flask. The system is allowed to reach equilibrium at 450oC. There is 0.10 mol Cl2 present at equilibrium. What is the equilibrium constant, K?

Equilibrium |

Chemometrics

Equilibrium : CalcRxnQuotient (13 Variations)In an experiment, 4.44 mol of SO2, 7.93 mol of O2 and 4.03 mol of SO3 are placed in a 2.0L reaction vessel at a certain temperature. Calculate the reaction quotient, Q, for the reaction as written:

What is the calculated reaction quotient, Q? {2:NUMERICAL:=2.1e-1:1e-2#Correct! ~%50%2.1e-1:5e-2#Close but not quite right}

If Kc for this reaction at the temperature of the experiment is 3.7 x 103, will the reaction move toward the left or toward the right? {1:MULTICHOICE:left#Sorry, that's wrong.~=right#Correct!}

Equilibrium |

Chemometrics

Equilibrium : CalcKp (2 Variations)
In one experiment chemists studied the formation of phosgene, COCl2, by mixing {y} atm of carbon monoxide and {z} atm of Cl2 in a reaction vessel at 700K. After the system reached equilibrium, the total pressure was {x} atm. Calculate Kp for the reaction.

Hint: Remember that the total pressure is the sum of all the partial pressures.

Note:
Do Not use scientific notation
DO NOT use spaces
DO NOT write in the units.
Be sure to write your answer with only one decimal place even if this is not the correct number of significant figures.

Equilibrium |

Chemometrics

Equilibrium : CalcKc (4 Variations)
A container initially has {y} M ammonia at a certain temperature. When the system reaches equilibrium the concentration of ammonia is {x} M. Calculate Kc for the following reaction as written.

Note:
Answers must be written using scientific notation with "e"
DO NOT use spaces
DO NOT write in the units.
Be sure to use three significant figures.
eg: 2.44e-5

Thermodynamics : GibbsFromHSandT (5 Variations)
On the space shuttle, the carbon dioxide produced by the astronauts is handled by an environmental control system that utilizes the following reaction.H° = -138.4 kJ and S° = -139 J/K
Calculate G° at 25°C for this reaction.

Thermodynamics |

Chemometrics

Thermodynamics : ATPFromGlucose (8 Variations)
When glucose is oxidized in the human body it releases a lot of Gibbs free energy. Rather than waste this free energy, the body stores much of it in the form of ATP. The following reaction shows this process of storing some of the energy from glucose in ATP. This is an example of coupled reactions in a biological system.
The label on a can of Coke says that it contains 39 g of sugar. Assume that all of the sugar is glucose (even though it isn't), and calculate how many moles of ATP can be produced theoretically by the oxidation of 39.0 g of glucose.

Enter your answer to ONE decimal place. DO NOT use scientic notation. DO NOT write in the units.

Acids / Bases |

Reactions |

Aqueous Solution Chemistry |

Equilibrium

Thermodynamics : EntropyPhaseChange (13 Variations)
Aluminum can be evaporated in a vacuum to form highly reflective coatings. Aluminum boils at 2792K and has a heat of vaporization of 70.0 kcal/mol. Calculate the entropy change for the vaporization of one mole of aluminum.